/*
     This file is part of GNUnet.
     Copyright (C) 2001, 2002, 2004-2007, 2009, 2016 GNUnet e.V.

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/

/**
 * @file statistics/gnunet-statistics.c
 * @brief tool to obtain statistics
 * @author Christian Grothoff
 * @author Igor Wronsky
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_statistics_service.h"
#include "statistics.h"


/**
 * Final status code.
 */
static int ret;

/**
 * Set to subsystem that we're going to get stats for (or NULL for all).
 */
static char *subsystem;

/**
 * Set to the specific stat value that we are after (or NULL for all).
 */
static char *name;

/**
 * Make the value that is being set persistent.
 */
static int persistent;

/**
 * Watch value continuously
 */
static int watch;

/**
 * Quiet mode
 */
static int quiet;

/**
 * Remote host
 */
static char *remote_host;

/**
 * Remote host's port
 */
static unsigned long long remote_port;

/**
 * Value to set
 */
static unsigned long long set_val;

/**
 * Set operation
 */
static int set_value;

/**
 * Handle for pending GET operation.
 */
static struct GNUNET_STATISTICS_GetHandle *gh;


/**
 * Callback function to process statistic values.
 *
 * @param cls closure
 * @param subsystem name of subsystem that created the statistic
 * @param name the name of the datum
 * @param value the current value
 * @param is_persistent #GNUNET_YES if the value is persistent, #GNUNET_NO if not
 * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
 */
static int
printer (void *cls,
         const char *subsystem,
         const char *name,
         uint64_t value,
         int is_persistent)
{
  struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get();
  const char *now_str;

  if (quiet == GNUNET_NO)
  {
    if (GNUNET_YES == watch)
    {
      now_str = GNUNET_STRINGS_absolute_time_to_string (now);
      FPRINTF (stdout,
	       "%24s %s%12s %50s: %16llu\n",
               now_str,
               is_persistent ? "!" : " ",
               subsystem,
	       _(name),
	       (unsigned long long) value);
    }
    else
    {
      FPRINTF (stdout,
	       "%s%12s %50s: %16llu\n",
               is_persistent ? "!" : " ",
               subsystem,
	       _(name),
	       (unsigned long long) value);
    }
  }
  else
    FPRINTF (stdout,
	     "%llu\n",
	     (unsigned long long) value);

  return GNUNET_OK;
}


/**
 * Function called last by the statistics code.
 *
 * @param cls closure
 * @param success #GNUNET_OK if statistics were
 *        successfully obtained, #GNUNET_SYSERR if not.
 */
static void
cleanup (void *cls,
         int success)
{
  gh = NULL;
  if (GNUNET_OK != success)
  {
    if (NULL == remote_host)
      FPRINTF (stderr,
               "%s",
               _("Failed to obtain statistics.\n"));
    else
      FPRINTF (stderr,
               _("Failed to obtain statistics from host `%s:%llu'\n"),
               remote_host,
               remote_port);
    ret = 1;
  }
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Function run on shutdown to clean up.
 *
 * @param cls the statistics handle
 */
static void
shutdown_task (void *cls)
{
  struct GNUNET_STATISTICS_Handle *h = cls;

  if (NULL == h)
    return;
  if (NULL != gh)
  {
    GNUNET_STATISTICS_get_cancel (gh);
    gh = NULL;
  }
  if ( (GNUNET_YES == watch) &&
       (NULL != subsystem) &&
       (NULL != name) )
    GNUNET_assert (GNUNET_OK ==
		   GNUNET_STATISTICS_watch_cancel (h,
                                                   subsystem,
                                                   name,
                                                   &printer,
						   h));
  GNUNET_STATISTICS_destroy (h,
                             GNUNET_NO);
  h = NULL;
}


/**
 * Main task that does the actual work.
 *
 * @param cls closure with our configuration
 */
static void
main_task (void *cls)
{
  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
  struct GNUNET_STATISTICS_Handle *h;

  if (set_value)
  {
    if (NULL == subsystem)
    {
      FPRINTF (stderr,
	       "%s",
	       _("Missing argument: subsystem \n"));
      ret = 1;
      return;
    }
    if (NULL == name)
    {
      FPRINTF (stderr,
	       "%s",
	       _("Missing argument: name\n"));
      ret = 1;
      return;
    }
    h = GNUNET_STATISTICS_create (subsystem,
				  cfg);
    if (NULL == h)
    {
      ret = 1;
      return;
    }
    GNUNET_STATISTICS_set (h,
                           name,
                           (uint64_t) set_val,
                           persistent);
    GNUNET_STATISTICS_destroy (h,
                               GNUNET_YES);
    h = NULL;
    return;
  }
  if (NULL == (h = GNUNET_STATISTICS_create ("gnunet-statistics",
                                             cfg)))
  {
    ret = 1;
    return;
  }
  if (GNUNET_NO == watch)
  {
    if (NULL ==
        (gh = GNUNET_STATISTICS_get (h,
                                     subsystem,
                                     name,
                                     &cleanup,
                                     &printer,
				     h)) )
      cleanup (h,
	       GNUNET_SYSERR);
  }
  else
  {
    if ( (NULL == subsystem) ||
	 (NULL == name) )
    {
      printf (_("No subsystem or name given\n"));
      GNUNET_STATISTICS_destroy (h,
				 GNUNET_NO);
      h = NULL;
      ret = 1;
      return;
    }
    if (GNUNET_OK !=
        GNUNET_STATISTICS_watch (h,
                                 subsystem,
                                 name,
                                 &printer,
				 h))
    {
      fprintf (stderr,
               _("Failed to initialize watch routine\n"));
      GNUNET_SCHEDULER_add_now (&shutdown_task,
                                h);
      return;
    }
  }
  GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
                                 h);
}


/**
 * Main function that will be run by the scheduler.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param cfg configuration
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct GNUNET_CONFIGURATION_Handle *c;

  c = (struct GNUNET_CONFIGURATION_Handle *) cfg;
  set_value = GNUNET_NO;
  if (NULL != args[0])
  {
    if (1 != SSCANF (args[0],
		     "%llu",
		     &set_val))
    {
      FPRINTF (stderr,
	       _("Invalid argument `%s'\n"),
	       args[0]);
      ret = 1;
      return;
    }
    set_value = GNUNET_YES;
  }
  if (NULL != remote_host)
  {
    if (0 == remote_port)
    {
      if (GNUNET_SYSERR ==
	  GNUNET_CONFIGURATION_get_value_number (cfg,
						 "statistics",
						 "PORT",
						 &remote_port))
      {
	FPRINTF (stderr,
		 _("A port is required to connect to host `%s'\n"),
		 remote_host);
	return;
      }
    }
    else if (65535 <= remote_port)
    {
      FPRINTF (stderr,
	       _("A port has to be between 1 and 65535 to connect to host `%s'\n"),
	       remote_host);
      return;
    }

    /* Manipulate configuration */
    GNUNET_CONFIGURATION_set_value_string (c,
					   "statistics",
					   "UNIXPATH",
					   "");
    GNUNET_CONFIGURATION_set_value_string (c,
					   "statistics",
					   "HOSTNAME",
					   remote_host);
    GNUNET_CONFIGURATION_set_value_number (c,
					   "statistics",
					   "PORT",
					   remote_port);
  }
  GNUNET_SCHEDULER_add_now (&main_task,
			    c);
}


/**
 * The main function to obtain statistics in GNUnet.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_string ('n',
                                 "name",
                                 "NAME",
                                 gettext_noop ("limit output to statistics for the given NAME"),
                                 &name),

    GNUNET_GETOPT_option_flag ('p',
                                  "persistent",
                                  gettext_noop ("make the value being set persistent"),
                                  &persistent),

    GNUNET_GETOPT_option_string ('s',
                                 "subsystem",
                                 "SUBSYSTEM",
                                 gettext_noop ("limit output to the given SUBSYSTEM"),
                                 &subsystem),

    GNUNET_GETOPT_option_flag ('q',
                                  "quiet",
                                  gettext_noop ("just print the statistics value"),
                                  &quiet),

    GNUNET_GETOPT_option_flag ('w',
                                  "watch",
                                  gettext_noop ("watch value continuously"),
                                  &watch),

    GNUNET_GETOPT_option_string ('r',
                                 "remote",
                                 "REMOTE",
                                 gettext_noop ("connect to remote host"),
                                 &remote_host),
    GNUNET_GETOPT_option_ulong ('o',
                                    "port",
                                    "PORT",
                                    gettext_noop ("port for remote host"),
                                    &remote_port),
    GNUNET_GETOPT_OPTION_END
  };
  remote_port = 0;
  remote_host = NULL;
  if (GNUNET_OK !=
      GNUNET_STRINGS_get_utf8_args (argc, argv,
				    &argc, &argv))
    return 2;

  ret = (GNUNET_OK ==
	 GNUNET_PROGRAM_run (argc,
			     argv,
			     "gnunet-statistics [options [value]]",
			     gettext_noop
			     ("Print statistics about GNUnet operations."),
			     options,
			     &run,
			     NULL)) ? ret : 1;
  GNUNET_free_non_null (remote_host);
  GNUNET_free ((void*) argv);
  return ret;
}

/* end of gnunet-statistics.c */
